Adapter assemblies for interconnecting surgical loading units and handle assemblies

ABSTRACT

An adapter assembly includes an elongated body, a switch, a sensor link, and an annular member. The elongated body includes a proximal portion configured to couple to a handle assembly and a distal portion configured to couple to a surgical loading unit. The switch is configured to be toggled in response to the surgical loading unit being coupled to the distal portion of the adapter assembly. The sensor link is disposed within the distal portion of the adapter assembly and biased toward a distal position. The sensor link is longitudinally movable between a proximal position and the distal position. The annular member is disposed within the distal portion and is rotatable between a first orientation, in which the annular member prevents distal movement of the sensor link, and a second orientation, in which the sensor link moves distally to toggle the switch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patent application Ser. No. 15/952,349, filed on Apr. 13, 2018, which is a Continuation Application of U.S. patent application Ser. No. 14/700,605, filed on Apr. 30, 2015 (now U.S. Pat. No. 10,561,418), which claims the benefit of and priority to U.S. Provisional Patent Application No. 62/017,626, filed Jun. 26, 2014, the entire disclosure of each of which is incorporated by reference herein.

BACKGROUND 1. Technical Field

The present disclosure relates to adapter assemblies for use with an electromechanical surgical system and their methods of use. More specifically, the present disclosure relates to hand-held, electromechanical surgical instruments capable of detecting the presence of a loading unit and/or identifying one or more parameters of a loading unit attached to an adapter assembly.

2. Background of Related Art

Linear clamping, cutting, and stapling surgical devices may be employed in surgical procedures to resect tissue. Conventional linear clamping, cutting, and stapling devices include a handle assembly, an elongated shaft and a distal portion. The distal portion includes a pair of scissors-styled gripping members, which clamp about the tissue. In this device, one or both of the two scissors-styled gripping members, such as the anvil portion, moves or pivots relative to the overall structure. The actuation of this scissoring device may be controlled by a grip trigger maintained in the handle.

In addition to the scissoring device, the distal portion may also include a stapling mechanism. One of the gripping members of the scissoring mechanism includes a staple cartridge receiving region and a mechanism for driving the staples up through the clamped end of the tissue against the anvil portion, thereby sealing the previously opened end. The scissoring elements may be integrally formed with the shaft or may be detachable such that various scissoring and stapling elements may be interchangeable.

A need exists for various types of adapter assemblies that communicate relevant information to a handle assembly upon a proper engagement of a loading unit with a handle assembly.

SUMMARY

The present disclosure relates to adapter assemblies for use between handle assemblies and loading units. The present disclosure also relates to mechanisms for toggling a switch of an adapter assembly for effectively communicating information about a loading unit to a handle assembly, which is coupled to the adapter assembly, upon engagement of the loading unit with the handle assembly.

According to an aspect of the present disclosure, an adapter assembly is provided. The adapter assembly includes an elongated body, a switch, a sensor link, and an annular member. The elongated body includes a proximal portion configured to couple to a handle assembly and a distal portion configured to couple to a surgical loading unit. The switch is configured to toggle in response to the surgical loading unit being coupled to the distal portion. The sensor link is disposed within the distal portion and biased toward a distal position. The sensor link is longitudinally movable between a proximal position and the distal position. The annular member is disposed within the distal portion and is rotatable between a first orientation, in which the annular member prevents distal movement of the sensor link, and a second orientation, in which the sensor link moves distally to toggle the switch.

In embodiments, the annular member may be electrically connected to the switch and the annular member may include at least one electrical contact configured to engage a corresponding electrical contact of the surgical loading unit.

In embodiments, the annular member may include a surface feature configured to interface with the surgical loading unit, such that the annular member is rotatable by the surgical loading unit. The surface feature may abut the sensor link to maintain the sensor link in the proximal position.

In embodiments, the sensor link may include a tab configured to engage the switch when the sensor link is in the distal position. The adapter assembly may further include a locking link disposed within the distal portion and have a distal end. The locking link may be resiliently biased toward a locking configuration to secure the surgical loading unit with the distal end of the locking link. The distal end of the locking link may include an extension configured for locking engagement with a lug of the surgical loading unit upon insertion and rotation of the surgical loading unit into the elongated body.

In another aspect of the present disclosure, an embodiment of a surgical instrument is provided. The surgical instrument includes a handle assembly, a surgical loading unit, and an adapter assembly. The handle assembly includes a motor and a processor configured to control the motor. The surgical loading unit has an end effector disposed at a distal end thereof. The surgical loading unit includes a memory configured to store at least one parameter relating to the surgical loading unit. The memory has a first electrical contact. The adapter assembly includes an elongated body including a proximal portion configured to couple to the handle assembly and a distal portion configured to couple to a proximal end of the surgical loading unit. The adapter assembly further includes a switch and an annular member. The switch is configured to couple the memory to the processor in response to the surgical loading unit being coupled to the distal portion. The annular member is disposed within the distal portion and electrically connected to the switch. The annular member includes a second electrical contact configured to engage the first electrical contact upon insertion of the surgical loading unit into the adapter assembly.

In embodiments, the surgical loading unit may further include an outer housing and an inner housing disposed within the outer housing. The memory may be attached to the inner housing and at least a portion of the first electrical contact is exposed.

In embodiments, the surgical loading unit may include a pair of opposing lugs disposed at a proximal end thereof. The adapter assembly may further include a sensor link disposed within the distal portion and biased toward a distal position. The sensor link may be longitudinally movable between a proximal position and the distal position. The annular member may be rotatable between a first orientation, in which the annular member prevents distal movement of the sensor link, and a second orientation, in which the sensor link moves distally into the distal position to actuate the switch. The annular member may include a surface feature configured to interface with a first one of the pair of lugs, such that the annular member is rotatable by the surgical loading unit. The sensor link may include a tab configured to engage the switch when the sensor link is in the distal position.

In embodiments, the adapter assembly may include a locking link disposed within the distal portion and having a distal end. The locking link may be resiliently biased toward a locking configuration to secure the surgical loading unit with the distal end of the locking link. The distal end of the locking link may include an extension configured for locking engagement with a second one of the pair of lugs upon insertion and rotation of the surgical loading unit into the elongated body. The annular member may include a tab configured to engage the distal end of the locking link when the locking link is in the locking configuration.

In embodiments, the at least one parameter stored by the memory may be a serial number of the loading unit, a type of the loading unit, a size of the loading unit, a staple size, a length of the loading unit, or number of uses of the loading unit.

In yet another aspect of the present disclosure, an embodiment of a surgical loading unit is provided. The surgical loading unit has a proximal portion configured for engagement with an adapter assembly of a surgical instrument and a distal portion having an end effector extending therefrom. The surgical loading unit includes a memory configured to store at least one parameter relating to the surgical loading unit. The memory includes an electrical contact and is configured to communicate to a handle assembly a presence of the surgical loading unit and the at least one parameter of the surgical loading unit upon engagement of the surgical loading unit with an adapter assembly.

As used herein, the term “toggle” is defined as a transition between a first condition, which is one of an actuated state or an unactuated state of a switch, and a second condition, which is the other of the actuated or unactuated states of the switch.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are described herein with reference to the accompanying drawings, wherein:

FIG. 1A is a perspective view of a hand-held, electromechanical surgical instrument, in accordance with an embodiment of the present disclosure;

FIG. 1B is a perspective view of an embodiment of an adapter assembly of the surgical instrument shown in FIG. 1A;

FIG. 1C is a side view of a surgical loading unit of the surgical instrument shown in FIG. 1 , including an end effector attached thereto;

FIG. 2 is a cutaway view of a distal portion of the adapter assembly shown in FIG. 1B, without a loading unit engaged therewith;

FIG. 3 is a perspective view of an annular member of the adapter assembly shown in FIG. 2 ;

FIG. 4 is a perspective view of the annular member shown in FIG. 3 electrically connected to a switch of the adapter assembly shown in FIG. 2 ;

FIG. 5 is an enlarged view of the distal portion of the adapter assembly shown in FIG. 2 , including the annular member and the switch assembled therein;

FIG. 6 is another cutaway view of the distal portion of the adapter assembly shown in FIG. 1B, without a loading unit engaged therewith;

FIGS. 7A and 7B are alternate cutaway views of the distal portion of the adapter assembly shown in FIG. 2 engaged with the loading unit, illustrating the annular member in a first orientation and a sensor link in a non-locking configuration;

FIGS. 8A and 8B are alternate cutaway views of the distal portion of the adapter assembly shown in FIG. 2 engaged with the loading unit, illustrating the annular member in a second orientation and the sensor link in a locking configuration;

FIG. 9 is an enlarged cutaway view of the distal portion of the adapter assembly shown in FIG. 2 ;

FIGS. 10A and 10B are alternate cutaway views of an outer housing of the loading unit shown in FIG. 1C;

FIGS. 11A and 11B are alternate perspective views of an inner housing of the loading unit shown in FIG. 1C;

FIGS. 12A and 12B are alternate views of the loading unit shown in FIG. 1C with the inner and outer housings assembled;

FIG. 13 is a cutaway view of the loading unit of FIG. 1C inserted into the annular member shown in FIG. 3 ;

FIG. 14 is a cross-section of the loading unit shown in FIG. 13 , taken along line 14-14;

FIG. 15 is a cross-section of the loading unit shown in FIG. 13 , taken along line 14-4 and distal to line 15-15; and

FIGS. 16A-16H are perspective views of alternate embodiments of electrical contacts of the annular member shown in FIG. 4 .

DETAILED DESCRIPTION

Embodiments of the presently disclosed surgical instruments, surgical loading units, and adapter assemblies for electromechanical surgical devices and/or handle assemblies are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the surgical instrument, adapter assembly, handle assembly, loading unit or components thereof, farther from the user, while the term “proximal” refers to that portion of the surgical instrument, adapter assembly, handle assembly, loading unit or components thereof, closer to the user.

With reference to FIGS. 1A-C, a surgical instrument, in accordance with an embodiment of the present disclosure, is generally designated as 10, and is in the form of a powered, hand-held, electromechanical surgical instrument including a handle assembly 100 configured for selective attachment thereto with any one of a number of adapter assemblies 200, and, in turn, each unique adapter assembly 200 is configured for selective connection with any number of surgical loading units 300. Loading unit 300 and adapter assembly 200 are configured for actuation and manipulation by handle assembly 100.

Reference may be made to International Publication No. WO 2009/039506 and U.S. Pat. No. 10,588,629, the entire contents of all of which are incorporated herein by reference, for a detailed description of the construction and operation of an exemplary electromechanical, hand-held, powered surgical instrument.

Handle assembly 100 includes one or more controllers (not shown), a power source (not shown), a processor 104, and a drive mechanism having one or more motors 106, gear selector boxes (not shown), gearing mechanisms (not shown), and the like. Processor 104 is configured to control motors 106 and to detect a presence of a loading unit, for example, loading unit 300, and/or determine one or more parameters of loading unit 300, as described herein. Handle assembly 100 further includes a control assembly 108. Control assembly 108 may include one or more finger-actuated control buttons, rocker devices, joystick or other directional controls, whose input is transferred to the drive mechanism to actuate adapter assembly 200 and loading unit 300.

In particular, the drive mechanism is configured to drive shafts and/or gear components in order to selectively move an end effector 304 of loading unit 300 to rotate end effector 304 about a longitudinal axis “X” defined by surgical instrument 10 relative to handle assembly 100, to move a cartridge assembly 308 relative to an anvil assembly 306 of end effector 304, and/or to fire a stapling and cutting cartridge within cartridge assembly 308 of end effector 304.

With continued reference to FIG. 1A, handle assembly 100 defines a nose or connecting portion 110 configured to accept a corresponding drive coupling assembly 210 of adapter assembly 200. Connecting portion 110 of handle assembly 100 has a cylindrical recess (not shown) that receives drive coupling assembly 210 of adapter assembly 200 when adapter assembly 200 is mated to handle assembly 100. Connecting portion 110 houses one or more rotatable drive connectors (not shown) that interface with corresponding rotatable connector sleeves of adapter assembly 200.

When adapter assembly 200 is mated to handle assembly 100, each of the rotatable drive connectors (not shown) of handle assembly 100 couples with a corresponding rotatable connector sleeve of adapter assembly 200. In this regard, the interface between a plurality of connectors of handle assembly 100 and a plurality of corresponding connector sleeves of the adapter assembly are keyed such that rotation of each of the drive connectors causes rotation of the corresponding connector sleeves of adapter assembly 200.

The mating of the drive connectors of handle assembly 100 with the connector sleeves of adapter assembly 200 allows rotational forces to be independently transmitted via each of the three respective connector interfaces. The drive connectors of handle assembly 100 are configured to be independently rotated by the drive mechanism.

Since each of the drive connectors of handle assembly 100 has a keyed and/or substantially non-rotatable interface with the respective connector sleeves of adapter assembly 200, when adapter assembly 200 is coupled to handle assembly 100, rotational force(s) are selectively transferred from drive mechanism of handle assembly 100 to adapter assembly 200.

The selective rotation of drive connector(s) of handle assembly 100 allows surgical instrument 10 to selectively actuate different functions of end effector 304. As discussed in greater detail below, selective and independent rotation of first drive connector of handle assembly 100 corresponds to the selective and independent opening and closing of end effector 304, and driving of a stapling/cutting component of end effector 304. Also, the selective and independent rotation of second drive connector of handle assembly 100 corresponds to the selective and independent articulation of end effector 304 about an articulation axis that is transverse to longitudinal axis “X.” In particular, end effector 304 defines a second or respective longitudinal axis and is movable from a first position in which the second or respective longitudinal axis is substantially aligned with longitudinal axis “X” to at least a second position in which the second longitudinal axis is disposed at a non-zero angle with respect to longitudinal axis “X.” Additionally, the selective and independent rotation of the third drive connector of handle assembly 100 corresponds to the selective and independent rotation of loading unit 300 about longitudinal axis “X” relative to handle assembly 100 of surgical instrument 10.

With continued reference to FIGS. 1A and 1B, adapter assembly 200 includes a knob housing 202 and an elongated body 204 extending from a distal end of knob housing 202. Knob housing 202 and elongated body 204 are configured and dimensioned to house the components of adapter assembly 200. Elongated body 204 may be dimensioned for endoscopic insertion. For example, elongated body 204 may be passable through a typical trocar port, cannula or the like. Knob housing 202 is dimensioned to not enter the trocar port, cannula of the like. Elongated body 204 has a proximal portion 206 a attached to knob housing 202, which is configured to be attached to handle assembly 100. Elongated body 204 has a distal portion 206 b configured to be coupled to proximal portion 302 a of loading unit 300. Elongated body 204 further includes a distal cap 208 extending distally from distal portion 206 b. Elongated body 204 further includes a cylindrical outer housing 212 and a cylindrical inner housing 214 (FIG. 2 ) disposed therein.

With reference to FIG. 2 , adapter assembly 200 further includes a switch 220, a sensor link or switch actuator 240, an annular member 260, and a locking link 280 (see FIG. 6 ), each being disposed within elongated body 204 of adapter assembly 200. Switch 220 is configured to toggle in response to a coupling of loading unit 300 to distal portion 206 b of elongated body 204. Switch 220 is configured to couple a memory 332 (FIG. 11A) of loading unit 300. The memory 332 may store data pertaining to loading unit 300 and is configured to provide the data to processor 104 of handle assembly 100 in response to loading unit 300 being coupled to distal portion 206 b of elongated body 204. Switch 220 is disposed within distal portion 206 b of inner housing 214 and is oriented in a proximal direction. In embodiments, switch 220 may be oriented in any suitable direction, such as, for example, a distal direction or a lateral direction. Switch 220 is mounted on a printed circuit board 222 that is electrically connected with processor 104 of handle assembly 100, such that upon toggling of switch 220, switch 220 communicates to handle assembly 100 that loading unit 300 is lockingly engaged to distal portion 206 b of elongated body 204 or that loading unit 300 is disengaged from distal portion 206 b of elongated body 204, as described in further detail below.

As mentioned above, adapter assembly 200 includes switch actuator 240 slidingly disposed within or along inner housing 214 of elongated body 204 and extends within distal portion 206 b of elongated body 204. Switch actuator 240 is longitudinally movable between a proximal position, as shown in FIGS. 2, 5, 7A, and 7B, and a distal position, as shown in FIGS. 8A and 8B. The switch actuator 240 toggles switch 220 during movement between proximal and distal positions. In embodiments, switch actuator 240 may actuate switch 220 when in the distal position or the proximal position.

Switch actuator 240 has a proximal end portion 242 a and a distal end portion 242 b. Proximal end portion 242 a includes an inner surface 244 that defines an elongated opening 246 having a biasing member, such as, for example, a coil spring 248 disposed therein. Coil spring 248 is secured within opening 246 between a distal end 244 a of inner surface 244 and a projection 250 of inner housing 214, which projects through opening 246.

Distal end portion 242 b of switch actuator 240 includes an extension 252 having a ramp portion 252 a. Extension 252 is engaged to a first surface feature 276 a of annular member 260 when annular member 260 is in a selected orientation relative to extension 252, such that switch actuator 240 is maintained in the proximal position. Switch actuator 240 further includes an appendage, such as, for example, a tab 254 extending from an intermediate portion 256 thereof. Coil spring 248 resiliently biases switch actuator 240 toward the distal position, as shown in FIGS. 8A and 8B, in which tab 254 actuates or depresses switch 220. In some embodiments, tab 254 actuates or depresses switch 220 when switch actuator 240 is in the distal position and unactuates switch 220 upon movement from the distal position to the proximal position.

With reference to FIGS. 2-5 , adapter assembly 200 includes annular member 260, which is rotatably disposed within inner housing 214 of elongated body 204. Annular member 260 extends from a proximal end 262 a to a distal end 262 b and defines a cylindrical passageway 264 therethrough configured for disposal of an inner housing 310 b of loading unit 300, as described in greater detail below with reference to FIGS. 9-15 . Annular member 260 includes a longitudinal bar 266 defining an elongated slot 268 along a length thereof configured for sliding disposal of a fin 320 of inner housing 310 b (FIG. 11A) of loading unit 300. Proximal end 262 a includes a first ring 270 a and distal end 262 b includes a second ring 270 b, spaced from first ring 270 a along longitudinal bar 266. First ring 270 a includes a pair of electrical contacts 272 electrically coupled to switch 220 via wires 274. Electrical contacts 272 are configured to engage corresponding electrical contacts 330 of loading unit 300, such that switch 220 and annular member 260 are capable of transferring data pertaining to loading unit 300 therebetween, as described in greater detail below. It is contemplated that a portion or portions of annular member 260 may be ring-shaped or that all of annular member 260 may be ring-shaped. The manner in which annular ring 260 captures loading unit 300 ensures that the corresponding electrical contacts 272, 330 make good electrical contacts in view of commercially achievable tolerance conditions.

With specific reference to FIGS. 3 and 4 , annular member 260 also includes a first surface feature 276 a, and a second surface feature, such as, for example, a tab 276 b, each extending from second ring 270 b. Surface feature 276 a of annular member 260 is configured to interface with a first surface feature or first lug 312 a (FIGS. 7A and 7B) of loading unit 300, such that annular member 260 is rotatable by and with loading unit 300. Specifically, surface feature 276 a defines a cavity 278 therein having a squared configuration configured for mating engagement with correspondingly shaped first lug 312 a of loading unit 300. In embodiments, cavity 278 may be of various shapes, such as, for example, triangular, rectangular, circular, variable, tapered, and/or polygonal. Cavity 278 is shaped and dimensioned to capture first lug 312 a (FIGS. 7A and 7B) of loading unit 300 upon insertion of loading unit 300 into adapter assembly 200, such that annular member 260 is rotatable with and by loading unit 300. Surface feature 276 a of annular member 260 is also configured to abut extension 252 of switch actuator 240 to maintain switch actuator 240 in the proximal position.

Annular member 260 is rotatable between a first orientation and a second orientation. In the first orientation, as shown in FIG. 2 , surface feature 276 a of annular member 260 is captured between a proximal lip 208 a of distal cap 208 and extension 252 of switch actuator 240. In this configuration, the surface feature 276 a prevents distal movement of switch actuator 240 from the proximal position to the distal position, thereby maintaining tab 254 of switch actuator 240 out of engagement with switch 220. Accordingly, surface feature 276 a of annular member 260 has a dual function for both maintaining switch actuator 240 in the proximal position, out of engagement with switch 220, and capturing first lug 312 a of loading unit 300 in cavity 278 to provide an interface between loading unit 300 and annular member 260.

In use, loading unit 300 is inserted within the distal end of elongated tube 204 to mate first lug 312 a of loading unit 300 with first surface feature 276 a of annular member 260, as shown in FIG. 7A. Loading unit 300 is rotated, in a direction indicated by arrow “A” (FIG. 2 ), to drive a rotation of annular member 260 from the first orientation to the second orientation. Rotation of annular member 260 from the first orientation to the second orientation disengages surface feature 276 a of annular member 260 from extension 252 of switch actuator 240 such that coil spring 248 of switch actuator 240 biases switch actuator 240 toward the distal position, in which switch 220 is toggled, as shown in FIG. 8A.

With continued reference to FIGS. 3 and 4 , annular member 260 further includes a projection or tab 276 b extending from second ring 270 b. Tab 276 b has a planar configuration and is configured to resist and/or prevent inadvertent rotation of annular member 260 within inner housing 214 when loading unit 300 is not engaged to adapter assembly 200. With specific reference to FIG. 6 , when annular member 260 is in the first orientation, tab 276 b is secured between a projection 208 b of distal cap 208 and a distal end 282 of locking link 280. Rotation of annular member 260 from the first orientation to the second orientation is resisted and/or prevented until locking link 280 is moved to a non-locking configuration, as described below. In this way, tab 276 b ensures that first surface feature 276 a of annular member 260 is maintained in abutment with extension 252 of switch actuator 240 thereby maintaining switch actuator 240 in the proximal position until loading unit 300 is engaged to adapter assembly 200.

With reference to FIGS. 6, 7B, and 8B, adapter assembly 200 further includes locking link 280, which is disposed within distal portion 206 b of adapter assembly 200. Locking link 280 is slidingly disposed within or along inner housing 214 of adapter assembly 200 and is resiliently biased toward a locking configuration, as shown in FIGS. 6 and 8B. In the locking configuration, a distal end or extension 282 of locking link 280 is engaged with distal cap 208. Extension 282 of locking link 280 is configured for locking engagement with a second surface feature, such as, for example, a second lug 312 b (FIGS. 7A and 7B) of loading unit 300 upon insertion and rotation of loading unit 300 into elongated body 204. As shown in FIG. 8B, the loading unit 300 engages adapter assembly 200 and locking link 280 in the locking configuration, second lug 312 b of loading unit 300 is captured in an enclosure 284 defined by extension 282 of locking link 280 and distal cap 208.

In operation, a surgical loading unit, such as, for example, loading unit 300, is inserted into distal end 206 b of elongated body 204 of adapter assembly 200 to matingly engage first lug 312 a of loading unit 300 within cavity 278 of surface feature 276 a of annular member 260, as shown in FIG. 7A. The insertion of loading unit 300 within adapter assembly 200 also engages second lug 312 b with extension 282 of locking link 280 to move locking link 280 in a proximal direction, as shown in the direction indicated by arrow “B” in FIG. 7B, to the non-locking configuration, and out of abutment with tab 276 b of annular member 260. In this way, extension 282 of locking link 280 is no longer prevents annular member 260 from rotating. With loading unit 300 in this initial insertion position within adapter assembly 200, switch actuator 240 remains in the proximal position out of engagement with switch 220.

To lockingly engage loading unit 300 with adapter assembly 200, loading unit 300 is rotated, in a direction indicated by arrow “C” in FIG. 8A, to drive a rotation of annular member 260, via the mating engagement between first lug 312 a of loading unit 300 and surface feature 276 a of annular member 260, from the first orientation to the second orientation. The rotation of annular member 260 from the first orientation to the second orientation displaces surface feature 276 a of annular member 260 away from extension 252 of switch actuator 240. With surface feature 276 a out of engagement with extension 252 of switch actuator 240, switch actuator 240 moves from the proximal position, as shown in FIG. 7A, to the distal position, as shown in FIG. 8A, via coil spring 248. As switch actuator 240 moves to the distal position, tab 254 of switch actuator 240 toggles switch 220, e.g., by depressing switch 220, as shown in FIG. 8A. Depressing or actuating switch 220 communicates to handle assembly 100 that loading unit 300 is lockingly engaged with adapter assembly 200 and is ready for operation.

The rotation of loading unit 300 also moves second lug 312 b of loading unit 300 into an inner groove 208 c defined in distal cap 208 and out of engagement with extension 282 of locking link 280. The resilient bias of locking link 280 drives an axial translation of locking link 280, in a direction indicated by arrow “D” in FIG. 8B, to dispose locking link 280 into the locking configuration. With locking link 280 in the locking configuration, second lug 312 b of loading unit 300 is captured within enclosure 284 defined by extension 282 of locking link 280 and inner groove 208 c of distal cap 208. Loading unit 300 is prevented from moving distally out of enclosure 284 due to an inner ledge 208 d of inner groove 208 c, and is prevented from rotating, in a direction indicated by arrow “E” shown in FIG. 8B, due to extension 282 of locking link 280. Therefore, loading unit 300 is releasably, lockingly engaged to adapter assembly 200.

To selectively release loading unit 300 from adapter assembly 200, a practitioner translates or pulls locking link 280 in a proximal direction, such that extension 282 of locking link 280 is no longer blocking second lug 312 b of loading unit 300 and loading unit 300 can be rotated. Loading unit 300 is rotated, in a direction indicated by arrow “F” in FIG. 8A, to move second lug 312 b of loading unit 300 out of abutment with inner ledge 208 d of distal cap 208. The rotation of loading unit 300 also drives the rotation of annular member 260 from the second orientation to the first orientation via the mating engagement of first lug 312 a of loading unit 300 and surface feature 276 a of annular member 260. As annular member 260 rotates, surface feature 276 a rides along ramp portion 252 a of extension 252 of switch actuator 240 to drive switch actuator 240 in a proximal direction until annular member 260 is in the first orientation and switch actuator 240 is in the proximal position, out of engagement with switch 220. Upon tab 254 of switch actuator 240 disengaging switch 220, switch 220 is toggled, which communicates to the handle assembly 100 that loading unit 300 is no longer lockingly engaged with adapter assembly 200 and not ready for operation.

To fully disengage loading unit 300 from adapter assembly 200, loading unit 300 is axially translated, in a distal direction, through distal cap 208, and out of elongated body 204 of adapter assembly 200. It is contemplated that upon handle assembly 100 detecting that loading unit 300 is not lockingly engaged to adapter assembly 200, power may be cut off from handle assembly 100, an alarm (e.g., audio and/or visual indication) may be issued, or combinations thereof.

Turning to FIGS. 1 and 9-15 , loading unit 300 of surgical instrument 10 will now be described in detail. Loading unit 300 has a proximal portion 302 a configured for engagement with distal end 206 b of elongated body 204 of adapter assembly 200. Loading unit 300 includes a distal portion 302 b having an end effector 304 extending therefrom. End effector 304 is pivotally attached to distal portion 302 b. End effector 304 includes an anvil assembly 306 and a cartridge assembly 308. Cartridge assembly 308 is pivotable in relation to anvil assembly 306 and is movable between an open or unclamped position and a closed or clamped position for insertion through a cannula of a trocar.

Reference may be made to U.S. Pat. No. 7,819,896, filed on Aug. 31, 2009, entitled “TOOL ASSEMBLY FOR A SURGICAL STAPLING DEVICE”, the entire content of which is incorporated herein by reference, for a detailed discussion of the construction and operation of an exemplary end effector.

Loading unit 300 further includes an outer housing 310 a and an inner housing 310 b disposed within outer housing 310 b. Outer housing 310 a has a cylindrical configuration and is preferably made from an electrically conductive material. Inner housing 310 b is preferably made with and insulating material. First and second lugs 312 a, 312 b are each disposed on an outer surface of a proximal end 314 of outer housing 310 a. First lug 312 a has a substantially rectangular cross-section corresponding to cavity 278 of surface feature 276 a of annular member 260. Second lug 312 b has a substantially rectangular cross-section corresponding to inner groove 208 c of distal cap 208. Proximal end 314 of outer housing 310 a is sized and dimensioned to be inserted through distal cap 208 to lockingly engage adapter assembly 200.

Outer housing 310 a defines a first notch 316 a and a second notch 316 b in a proximal-most edge thereof. First notch 316 a is configured for sliding receipt of a tapered fin 320 extending from inner housing 210 b. At least a portion of fin 320 is configured for disposal in slot 268 defined in longitudinal bar 266 of annular member 260 to facilitate insertion of inner housing 310 b into annular member 260. Second notch 316 b is configured for a snap fit engagement with a pair of parallel, resilient fingers 322 of inner housing 310 b. Second notch 316 b generally has a rectangular configuration with a pair of grooves 318 defined therein. Each finger 322 has a mating part 324 configured for mating engagement with one respective groove 318 of second notch 316 b. Outer housing 310 a further defines a pair of channels 326 defined in an interior surface 328 thereof and disposed on either side of first notch 316 a. Each channel 326 of outer housing 310 a is configured for disposal of a portion of an electrical contact 330 of inner housing 310 b, as described in greater detail below.

In use, fin 320 and fingers 322 of inner housing 310 b are aligned with first and second notches 316 a, 316 b of outer housing 310 a, respectively, and inner housing 310 b is axially translated within outer housing 310 a, until mating parts 324 of fingers 322 are captured in grooves 318 of second notch 316 b to capture inner housing 310 b within outer housing 310 a. In embodiments, other mating mechanisms may be utilized to couple outer and inner housings 310 a and 310 b. In further embodiments, the outer and inner housings 310 a and 310 b may be integrally formed as a single housing.

Loading unit 300 further includes a memory 332 disposed within or on inner housing 310 b. Memory 332 includes a memory chip 334 (e.g., an EEPROM, EPROM, or any non-transitory storage chip) and a pair of electrical contacts 330 electrically connected to memory chip 334. Memory chip 334 is configured to store one or more parameters relating to surgical loading unit 300. The parameter may include at least one of a serial number of a loading unit, a type of loading unit, a size of loading unit, a staple size, information identifying whether the loading unit has been fired, a length of a loading unit, maximum number of uses of a loading unit, and combinations thereof. Memory chip 334 is configured to communicate to handle assembly 100 a presence of loading unit 300 and one or more of the parameters of loading unit 300 described herein, via electrical contacts 330, upon engagement of loading unit 300 with adapter assembly 200.

Electrical contacts 330 are disposed on an outer surface of inner housing 310 b and are configured to engage electrical contacts 272 of annular member 260 upon insertion of loading unit 300 into adapter assembly 200. A proximal end of each electrical contact 330 has a bent portion 336 configured to be exposed and/or to extend beyond a proximal-most edge of outer housing 310 a of loading unit 300 when inner housing 310 b is secured within outer housing 310 a, as shown in FIGS. 12A and 12B. Bent portions 336 of electrical contacts 330 of loading unit 330 engage electrical contacts 272 of annular member 260 upon insertion of loading unit 300 within annular member 260 of adapter assembly 200. This connection between the contacts 272 and 330 allows for communication between memory chip 334 of loading unit 300 and processor 104 of handle assembly 100. In particular, the processor 104 receives one or more parameters pertaining to loading unit 300 and/or that loading unit 300 is lockingly engaged to adapter assembly 200.

In operation, loading unit 300, with inner housing 310 b disposed within outer housing 310 a, is manipulated to align fin 320 of inner housing 310 b and electrical contacts 330 of inner housing 310 b with longitudinal bar 266 of annular member 260 and electrical contacts 272 of annular member 260, respectively. Loading unit 300 is inserted within distal end 206 b of adapter assembly 200 thereby engaging first lug 312 a of outer housing 310 a within surface feature 276 a of annular member 260 and forming a wiping contact between electrical contacts 330 of inner housing 310 b and electrical contacts 272 of annular member 260, as shown in FIGS. 13-15 .

As described above with reference to FIGS. 1-8 , upon the initial insertion of loading unit 300 into adapter assembly 200, switch actuator 240 remains disengaged from switch 220. With switch 220 in the unactuated state, there is no electrical connection established between memory chip 334 of loading unit 300 and processor 104 of handle assembly 100. As discussed above, upon a rotation of loading unit 300, loading unit 300 lockingly engages adapter assembly 200 and switch actuator 240 toggles switch 220 to actuate switch 220. With switch 220 in the actuated state, an electrical connection is established between memory chip 334 and processor 104, through which information about the loading unit 300 is communicated to processor 104 of handle assembly 100. Upon both the actuation of switch 220 and the formation of a wiping contact between electrical contacts 330 of inner housing 310 b and electrical contacts 272 of annular member 260, handle assembly 100 is able to detect that loading unit 300 has been lockingly engaged to adapter assembly 200 and to identify one or more parameters of loading unit 300.

While an electrical interface between loading unit 300 and handle assembly 100 is shown and described, it is contemplated that any other form or communication is within the scope of the present disclosure, for transmitting any or all of the operating parameters and/or the life-cycle information from loading unit 300 to handle assembly 200, such as, for example, wireless communication, including various radio frequency protocols such as near field communication, radio frequency identification “RFID,” BLUETOOTH®, etc.

In further embodiments, as shown in FIGS. 16A-F, 17A, and 17B, electrical contacts 272 of annular member 260 can be variously configured to help reduce wear on the attachment (e.g., solder) interface between electrical contacts 272 and annular member 260 while annular member 260 is rotated between the first and second orientations.

FIGS. 16A and 16B illustrate electrical contacts 372, 472 having a wire “W” soldered thereto such that wire “W” is in a linear configuration and in line with surgical instrument 10. FIG. 16C illustrates an electrical contact 572 having a wire “W” soldered thereto such that wire “W” has a bent configuration.

FIGS. 16D-F illustrate electrical contacts 672, 772, 872 having a key-shaped opening 672 a, 772 a, 872 a defined therein configured for disposal of a wire “W.” Key-shaped openings 672 a, 772 a, 872 a each have a sharp edge 672 b, 772 b, 872 b that penetrates an insulative coating of wire “W” during attachment of wire “W” to electrical contacts 672, 772, 872 to establish metal on metal contact without soldering.

FIGS. 16G and 16H illustrate electrical contacts 972, 1072 having a bendable tab 972 a, 1072 a that can be crimped over a wire “W” to secure wire “W” therewith. It is contemplated that each of the above described electrical contacts are configured so that wires “W,” which are soldered, crimped, and/or attached thereto in any suitable manner, can be in coaxial alignment with a longitudinal axis that extends through surgical instrument 10.

It will be understood that various modifications may be made to the embodiments of the presently disclosed adapter assemblies. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure. 

What is claimed is:
 1. A surgical instrument comprising: a surgical loading unit having a lug; a switch configured to be actuated in response to the surgical loading unit being coupled to the surgical instrument; and an annular member configured to capture the lug of the surgical loading unit and for preventing an actuation of the switch, wherein the annular member is configured to rotate relative to the switch between a first orientation, in which the annular member prevents actuation of the switch, and a second orientation in which the annular member does not prevent actuation of the switch.
 2. The surgical instrument according to claim 1, further comprising an elongated body including a distal portion configured to couple to the surgical loading unit.
 3. The surgical instrument according to claim 2, wherein the annular member is rotatably coupled to the distal portion of the elongated body.
 4. The surgical instrument according to claim 3, wherein the annular member is configured to rotate relative to the distal portion of the elongated body between a first orientation, in which the annular member prevents actuation of the switch, and a second orientation, in which the annular member permits actuation of the switch.
 5. The surgical instrument according to claim 4, further comprising a switch actuator movably coupled to the elongated body portion, wherein the annular member prevents movement of the switch actuator from a proximal position to a distal position when the annular member is in the first orientation, and the switch actuator is configured to move from the proximal position to the distal position to actuate the switch when the annular member is moved from the first orientation toward the second orientation.
 6. The surgical instrument according to claim 1, wherein the annular member includes a ring body, and a surface feature protruding outwardly from the ring body, the surface feature being configured to capture the lug of the surgical loading unit.
 7. The surgical instrument according to claim 6, further comprising a switch actuator having a distal end portion configured to engage the surface feature of the annular member whereby the surface feature prevents distal movement of the switch actuator.
 8. The surgical instrument according to claim 7, wherein the switch actuator has a tab configured to actuate the switch when the surface feature of the annular member is moved out of engagement with the distal end portion of the switch actuator.
 9. The surgical instrument according to claim 8, wherein the annular member prevents movement of the switch actuator from a first position to a second position when the annular member is in a first orientation, and the switch actuator is configured to move from the first position to the second position to actuate the switch when the annular member is moved from the first orientation toward a second orientation.
 10. The surgical instrument according to claim 1, wherein the annular member is configured to be rotated by the surgical loading unit when the lug of the surgical loading unit is captured by the annular member.
 11. The surgical instrument according to claim 1, wherein the annular member is electrically connected to the switch and the annular member includes at least one electrical contact configured to engage a corresponding electrical contact of the surgical loading unit.
 12. The surgical instrument according to claim 11, wherein the surgical loading unit has a memory configured to store at least one parameter of the surgical loading unit, the memory having a first electrical contact.
 13. The surgical instrument according to claim 12, wherein the annular member includes a second electrical contact configured to engage the first electrical contact upon capturing of the lug of the surgical loading unit by the annular member. 